Akira Takarada

Comparisons of detailed arterial healing response at seven months following implantation of an everolimus- or sirolimus-eluting stent in patients with ST-segment elevation myocardial infarction

BACKGROUND The difference of arterial healing response following everolimus-eluting stent (EES) or sirolimus-eluting stent (SES) implantation in patients with ST-segment elevated myocardial infarction (STEMI) has not been compared in detail. METHODS Thirty-five patients with STEMI were randomly implanted with an EES or SES (23 EES, 12 SES). At seven months, neointimal thickness (NIT) and strut malapposition were evaluated by optical coherence tomography (OCT) and the grade and heterogeneity of neointimal coverage (NIC) and development of intra-stent thrombi were evaluated by angioscopy. RESULTS No significant differences were noted in clinical events experienced by the two groups, although one patient with an EES died following a papillary muscle rupture and one patient with a SES experienced sub-acute stent thrombosis. On OCT, although the EES implants showed a greater NIT than the SES implants (94.8 ± 88.8 μm vs 65.6 ± 63.3 μm, P<0.0001), both the EES and SES showed an excellent suppression of neointimal proliferation in the culprit lesion of STEMI. The frequency of uncovered and malapposed struts of EES was significantly lower than that of SES (2.7% vs. 15.7%, P<0.0001, 0.7% vs. 2.3%, P<0.0001, respectively). The ratio of stents fully covered with neointima of EES group was significantly higher than that of SES group (P=0.04). Angioscopic analysis also showed greater dominant NIC grade with homogenous NIC in EES than in SES (P=0.03, P=0.0002, respectively). The incidence of massive intra-stent thrombus of EES was lower than that of SES (P=0.05). CONCLUSION For patients with STEMI, EES may promote better arterial healing response than SES.

Possible association between non-invasive parameter of flow-mediated dilatation in brachial artery and whole coronary plaque vulnerability in patients with coronary artery disease.

BACKGROUND Despite being a relatively widely-used non-invasive parameter of endothelial dysfunction, little is known regarding the relationship between flow-mediated dilatation (FMD) and coronary plaque vulnerability in patients with coronary artery disease (CAD). METHODS 111 CAD patients (age; 68.9 ± 9.3) who underwent both coronary intervention and FMD were enrolled. Spectral analyses of intravascular ultrasound radiofrequency data for both culprit and non-culprit lesions were performed using Virtual Histology software. Plaque burden was described based on fibrotic, fibro-fatty, dense calcium, and necrotic core (NC) components, and thin-cap fibroatheroma (TCFA) was defined as focal NC rich (> 10%) plaques touching the lumen with a percent-plaque volume exceeding 40%. RESULTS Averaged %FMD was 2.86 ± 2.03% (median 2.27%, 25th 1.40%, 75th 4.20%). NC volumes were negatively correlated with log%FMD for both culprit and non-culprit lesions (P = 0.001, r = 0.31 and P = 0.03, r = 0.21, respectively). We divided the patients into three tertiles according to %FMD; 38 were lower (≤ 1.75%), 41 were middle (> 1.75%, but ≤ 3.5%), and 32 were upper tertile (> 3.5%). The prevalence rate of TCFA increased with decreasing %FMD tertile and the incidence of major adverse cardiac events was significantly higher in lower %FMD tertile. Multivariate logistic regression analyses showed that the most powerful predictive factor for TCFA was log%FMD (P < 0.0001), and ROC curve analysis identified %FMD of < 2.81% (AUC = 0.82, sensitivity: 91.2%, specificity: 66.7%) as the optimal cut-off point for predicting the presence of TCFA. CONCLUSIONS Impaired endothelial function in brachial arteries may be associated with whole coronary plaque vulnerability and poor clinical outcome in patients with CAD.

Detailed comparison of intra-stent conditions 12 months after implantation of everolimus-eluting stents in patients with ST-segment elevation myocardial infarction or stable angina pectoris.

BACKGROUND The differences in lesion morphology between ST-segment elevation myocardial infarction (STEMI) and stable angina (SAP) significantly influence chronic intra-stent conditions after first-generation drug-eluting stent implantation. The study aimed to compare the intra-stent conditions 12 months after implantation of a second-generation everolimus-eluting stent (EES) in patients with STEMI or SAP. METHODS AND RESULTS We examined the lesion morphology before EES implantation in 53 patients (23 STEMI, 30 SAP) using virtual histology intravascular ultrasound. We maintained dual anti-platelet therapy for 12 months and subsequently analyzed intra-stent conditions using optical coherence tomography and angioscopy. Pre-intervention plaque and necrotic core volume/length, remodeling index, and the incidence of thin-cap fibroatheroma and thrombus were significantly greater in STEMI than in SAP. After 12 months, the median neointimal thickness (117.6 μm vs. 126.0 μm), frequency of uncovered struts (1.2% ± 2.3% vs. 1.0% ± 2.3%), and percentage of stents fully covered with neointima (60.9% vs. 61.1%) were similar between the 2 groups. Meanwhile, the frequency of malapposed struts (0.4% ± 0.6% vs. 0.1% ± 0.4%, p=0.04) and neointimal unevenness score (1.74 ± 0.21 vs. 1.64 ± 0.16, p=0.04) were significantly higher in STEMI than in SAP. The neointimal color grade was more xanthochromatic in STEMI than in SAP. However, the differences were not associated with the incidence of clinical events and intra-stent thrombus (21.7% vs. 16.7%, p=0.89). CONCLUSIONS Although a small degree of delayed healing still persists with second-generation EES, EES promotes a favorable arterial healing response in patients with STEMI, as well as those with SAP.

Change of the new left ventricular function index (TEI INDEX) in acute myocardial infarction

It is well known that restrictive transmitral flow(TMF) pattern is predictive of higher cardiac mortality in patients(pts) with chronic heart failure(CHF). However, prognostic value of non-restrictive TMF pattem(NR) in pts with CHF is still unknown. We evaluated changes in left ventdcular(LV) filling with low dose dobutamine stress echocardiography(DSE) and assessed the prognostic significance of changes of LV filling in pts with CHF showing NR. Low dose (10mcg /kg/min) DSE was performed in 45 pts(36men, age 60+11 years) with CHF(35 pts with prior myocardial infarction, 10 with dilated cardiomyopathy) in NYHA class I1-111 with a mean LVEF of 40+13%. Pts were followed over 22+7 months for cardiac events. We measured peak velocities of eady(E) and late(A) diastolic TMF. Isovotumetdc relaxation time(IRT:msec) and deceleration time(DT:msec) of TMF were also measured. We obtained LV outflow time-velocity integrals(OTI) as an index of stroke volume. Then, we evaluated the relations between the changes(A) of these variables during DSE and cardiac events. Pts were subdivided into two groups who had cardiac events(CE:16pts) and had not(NCE:29pts)during followed period. In NCE, percent& IRT shortened significantly during DSE compared to that in CE (NCE:-25% vs CE:-2.4%, p<0.01).ADT,&A/E and AOTI did no~ differ between the two groups. Multivariate analysis showed thatA IRT was the only independent predictor of cardiac events (p<0.01). Conclusions: The shortening of IRT with dobutamine was significantly related to less cardiac event in pts with CHF, suggesting that preserved lusitropy might have favorable effects on the clinical outcome in pts with CHF. Assessment of LV diastolic property with DSE might be useful to predict the outcome in pts with mild to moderate CHF.